Early wheat greenup creates concerns about crop

Wheat in much of Kansas has broken dormancy and started greening up.
Plants growing at this time of year use valuable soil moisture.
Plants will have lost some of their winter hardiness.

Mar 07, 2012

Unusually warm weather in late February and early March and good topsoil moisture levels, except in far southwest Kansas, have caused wheat in much of Kansas to break dormancy and start greening up, said Jim Shroyer, K-State Research and Extension crop production specialist.

“This is a scenario somewhat reminiscent of 2007, which was a year with severe spring freeze injury. Hopefully we will avoid that this year,” Shroyer said. “The wheat has begun to grow as a result of several days with temperatures in the 60s and nighttime temperatures above freezing. It would be much better if temperatures were colder.”

Plants growing at this time of year use valuable soil moisture, he said. Even though topsoil moisture is adequate in most of Kansas, the moisture would be better used later in the growing season.

In addition, plants will have lost some of their winter hardiness, he said.

“This won’t be a problem if the weather never turns extremely cold again this month or if temperatures cool down gradually so the plants can regain some of their winter hardiness. If the wheat is green and growing, however, and temperatures suddenly go from unusually warm to extremely cold, freeze injury could occur,” Shroyer said.

The warm weather could also result in early-season insect and disease problems.

“Army cutworms are sometimes a problem in wheat fields during March. Other early-spring insects to watch include winter grain mites and greenbugs. Early-season disease concerns include powdery mildew and tan spot,” he said.

“Producers should watch their wheat crops for insects and diseases, and make every effort to get on their topdress nitrogen soon, before the crop reaches the jointing stage –if they haven’t already done so,” Shroyer advised.

“Other than that, there’s not much that producers can do to stop the development of the crop. Grazing the wheat can hold back its development, but grazing may not be possible much longer this winter. Cattle should be pulled off before first hollow stem, and this will be occurring soon in southern Kansas, if it hasn’t already occurred.”

The longer temperatures remain above normal, the more susceptible the wheat will be to a sudden temperature drop to the single digits or below, Shroyer said.